Antibacterial agent 255 (compound (±)-1) is a potent antibacterial agent. Antibacterial agent 255 is a potent and selective 4-diphosphocytidyl-2-C-methyl-D-erythritol (IspE) inhibitor with IC 50 values of 13.0, 8.0, 20 µM for EclspE, KplspE, AblspE, respectively.